Method of reproducing phonograph-records.



no. 645,920. Patented Mar'. 20, v|000.

T. B.`LAMBERT.

METHOD 0F BEPBODUCING PHONUGRAPH RECORDS.

(Application lad Aug. 14, 1899.)

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HW l f 0 lllEI Mmm NITED STATES PATENT Finca.

THOMAS B. LAMBERT, OF CHICAGO, ILLINOIS, ASSIGNOR OF TIIREE-FIFTHS TO BRIAN F. PI-IILPOT AND JOSEPH POWELL, OF SAME PLACE.

METHOD OF REPRODUCING PHONOGRAPIPRECORDS.

SPECIFICATION forming part of Letters I atent No. 645,920, dated March 20, 1900. Appiicanonmediiuguai4,1899. Santino. 727,183. (Nummer.)

certainnew and useful Improvements in Processes for Producing Record -Cylinders for Phonographs, of whichA the following is a specification.

My invention relates. to that class of mech anisms which are styled record cylinders and which are adaptedA to be used in connection with phonographs and similar instruments-that, is, instruments adapted toV be operated for the purpose of'vibrating a dia phragm and imitating speech and musical notes.

. provide'a simple, economical, and eicient method for constructing infrangible `recordcylinders. y l

A further object ofthe invention is to pro- Vide a record-cylinder of such material-as to render it practically infrangible and the in- Vention consists in the methods, features, combinations, and details of construction hereinafter described and claimed.

In the drawings, Figure l is a vertical sec-v tional elevation of a bath containing an electrolytic solution adapted to electrically form a matrix by which a record-cylinder for phonographs may be produced, showing other elements attached, as will be more fully hereinafter explained; Fig. 2, a plan view of a completed matrix, and Fig. 3 a perspective view of a completed record-cylinder.

In the art to which this invention relates it is well known that it is desirable to produce a record-cylinder of such nature and construction as will make it practically indestructible, and, further,to provide means and methods by which such a cylinder can be economically and efficiently formed and duthe impressions on the wax cylinder. desirable now to produce. the indestructible 'record-cylinders from this copper matrix in plicated in quantities as desired. To these features my invention principally relates.

In forming a record-cylinder I first take and'make an impression upon a wax cylinder A (see Eig. 1, in which the wax cylinder is in theb'ath) in an ordinary phonograph,and then remove this Wax cylinder from the phonograph and provide it at one end with a coatingzofcarbon B or otherA electric conducting material. I next place this cylinder in an electrolytic bath, having first surrounded and connected it with a metal ring C, which is supported on a vmetal Arod D by means of av Wire d and connected with the negative pole of a dynamo E. This cylinder, with 4its attached mechanism, is `t h, nplaced,vas above suggested, in ,the electrolytic bath, which brings,` it in lcircuit Iwith,l the anode tGr, of copper vor other metal, hung by lmeansof. a metal wire g upon a metal rod H and con nected with the other pole of the' dynamo. The dynamo being started,lthecopper is elec-V trically deposited upon the'carbon-coated desired thickness forms a copper cylinder,

.which is then removed from the bath and dis-A lconnected from `the dynamo. v,The wax is next shrunk by means of cold application, so that the coppercylinder may be removed therefrom. These operations form a copper cylindrical matrixb, the inner cylindrical surface of Which contains a counterpart of It is 8s quantities as desired. vTo kaccomplish this result, the matrix is placed inside of a metal ring I, considerably larger in diameter than the matrix, and the space between the same filled with type-metal I', which securely locks the matrix in position and furnishes a iirm backingvfor the same. I next take a soft ring of cellulose or vulcanized rubber, either in a raw or partially-cured state or previously softened with somev solution and of sucient thickness to receive in perfect form the indentations of the matrix and at the saine time furnish a suitable backing or support for the phonographic -reproduction of the record. This relatively-thick ring or tube is then IOO ` sure with heat forced outwardly, completely filling the matrix and against the inner surface thereof, thus making a counterpart of the same and a record similar to that on the original wax cylinder. The ring thus formed, having on its outer face a faithful imprint of the matrix, is then allowed to harden, either naturally or by artificially curing the substance thereof, through which hardening it shrinks sufficiently to enable its subsequent removal to be made from the matrix without injury to either. As a shrinking or reducing medium I have used a solution of hydrochlorous acid and water in which the tube and matrix are placed, as above, so that the tube can be removed from its engagement with the matrix. When it has become dried and hardened, it forms a cylinder K, as shown in perspective View in Fig. 3, preferably of cellulose,and which is practically infrangible. I prefer to use cellulose for this purpose in t-hat it'is easier to manufacture and more durable in operation, though the same method may be used for forming cylinders of different materials.

In carrying out my process it is an absolute requirement that the blank phonograms or tubes must be of a thickness to receive and retain in a perfect form the indentations of the matrix and at the same time have Within itself a suiiicient backing or support for the reproduction of the record phonographically after the formation of the record ou its face and the removal of the tube from the matrix. It is practically impossible to use very thin walled tubes or hollow cylinders for my process, because the phonographic reproduction of sound from such thin records, supposing the tubes to be capable of even temporarily maintaining or holding their shape, would be weak, distorted, indistinct, and imperfect; but as a matter of fact the records themselves made of thin material are not capable of retaining their shape and would be impractical in actual use. By using a relatively-thickwalled tube or hollow cylinder the objections which would occur in practice with a very thin tube are entirely overcome and the producedy records are a merchantable article. It

is to be understood that in applying pressure to the interior of the tube or cylinder for forcing the same outwardly and against the face of the matrix such pressure must be simultaneously exerted over the entire surface of the tube or cylinder and in a uniform manner, so as to simultaneously force -the entire exterior surface against the interior face of the matrix, for if otherwise there would be great danger and liability of a iiow of material and a consequent distortion therefrom, producing an imperfect record.

I claimn l. The method of producing record-cylin ders for phonograplis, which consists in first forming a record 011 a cylinder of wax or other relatively-soft material, rendering the surface of the wax cylinder electrically conductive and electrolytieall y deposit-ing metal thereon, forming a matrix and then outwardlyexpanding under pressure within the matrix, a cylinder or tube of softened material suiiieiently thick to maintain its shape during and after the act of disengagement from the matrix and finally removing the cylinder or tube by di` 4rect longitudinal movement, substantially as described.

2. The method of producing record-cylinders for phonographs which consists :in first forming a record on a cylinder of relativelysoft material such as wax, then coating such cylinder with carbon or other electric conducting material, and electrolytically depositing metal thereon forming a matrix, then shrinking the soft cylinder to remove the electrically-formed matrix and backing such matrix to form a matrix-mold, then outwardly expanding under pressure a cylinder or tube suiiiciently thick to maintain its shape after disengagement from the matrix and of softened material such as cellulose, within the matrix for the pressure to reproduce on the outer surface the counterpart of the indentations in the matrix, then allowing such cellulose cylinder or tube to harden within the matrix and removing the record cylinder or tube from the matrix and then drying and hardening the record-cylinder, substantially as described.

, THOMAS B. LAMBERT.

Witnesses:

THOMAS F. SHERIDAN, ALBERT D. PHiLPoT. 

